Do I Need Planning Permission for a Garden Room?

In recent years, garden rooms have surged in popularity across the UK. Whether you’re dreaming of a home office, gym, art studio, or a quiet retreat, a garden room is a brilliant way to make the most of your outdoor space and your property.

But before you start building, one big question usually comes up:

Do you need planning permission (PP) for a garden room?

Let’s break it down. Before you need to know about your permissions, you need to know…

What Is Permitted Development?

Permitted Development (PD) rights allow homeowners to carry out certain types of work on their property without the need to apply for a full planning permission. The government sets out these rules to make smaller projects, like loft conversions or outbuildings, simpler to complete

Garden rooms often fall under these rights, but there are specific criteria you need to meet.

When Can I Build a Garden Room Without Planning Permission?

Most garden rooms don’t require planning permission—if they follow these rules:

•  It’s a detached outbuilding
  The garden room must be separate from the main house.
•  It’s for “incidental” use
  This means it’s not for sleeping or everyday living. 

Offices, gyms, hobby spaces, studios = OK. Bedrooms or kitchens = not OK.

• It follows height restrictions:

• Single Storey ONLY
• Up to 2.5m high if it’s within 2m of any boundary (e.g. fence or neighbour’s wall)
• • Up to 4m high with a dual-pitched roof if it’s more than 2m from a boundary
    
    
  • Up to 3m for a flat roof more than 2m from the boundary
    
    
  • It doesn’t take up too much garden space; the structure must not cover more than 50% of the land around the original house
    
    
  • Internal floor space must be under 30m²
  • It’s not in front of your house
  Garden rooms must be located near the rear or side of the garden, not forward of the principal elevation (the front of the house).

When Do You Need Planning Permission?

Even if your build meets most PD criteria, you’ll likely still need planning permission if:

• Your property is a listed building
• You live in a designated area, AONB, national park, or World Heritage Site
• You plan to use the room as a self-contained living space
• The garden room exceeds the height or size limits

Can I live in my garden room?
Not without planning permission. Living in it, sleeping in it, or renting it out turns it into a  “dwelling”, which will require permission.

Do I Need Building Regulations for a Garden Room?

Not always. You usually don’t need building regs if:

• It’s under 15m²
  
  

• It’s not used for sleeping accommodation
  
  

• It doesn’t include plumbing or heating systems
  

💡 Top tip: Even if you don’t need planning permission, you might still need building regs. Always check with your local building control office before starting.

Garden Room Planning FAQs

Can I put a garden room next to a fence?
Yes—if the garden room is 2.5m high or less, you can build it right up to the boundary.

Can I build a garden room with a toilet?
You’ll likely need building regulations approval, even if planning permission isn’t needed.

Do I need permission for a garden office or gym?
Not usually. These are considered incidental uses under Permitted Development.

Can I put a garden room in my front garden?
No. PD rights don’t cover garden rooms in front of the main house.

Can I sleep in my garden room?
No—sleeping or living in a garden room without planning permission is not allowed.

Still Not Sure? Here’s What to Do:

If you’re unsure, here are two easy ways to move forward:

Contact your local planning authority – They’ll confirm if your property has full PD rights.

Final Overview

A garden room is one of the easiest ways to expand your home without moving, adding space, value and functionality to your home, but it pays to know the rules and avoid costly mistakes.

Need advice on your project?
Get in touch for a free consultation with our garden room experts.